1. Field of Invention
This application is directed to an electronic system for displaying changing views. In particular, the invention is directed to permitting freeform digital ink annotation on electronic media and to maintaining the logical relationship between freeform digital ink annotations and objects in changing views of the media.
2. Description of Related Art
Freeform ink annotation of paper documents is a wide-spread practice because it aids many aspects of document work, including the processes of thinking, categorizing and reviewing. In short, freeform ink annotation has proven to be a powerful comprehension tool. Paper and paper-like documents (such as PDF, postscript, image files, etc.) have a static layout and content. The static nature of these documents makes annotation simple.
However, the kinds of documents that people use are increasingly created and presented digitally on displays using computers. Such documents are often dynamic and, therefore, the accurate representation of the relationship of the annotations to objects in the display has been impossible because of the changing display. For example, a display of a word processor document changes as the document is undergoing revisions. In a similar manner, information visualization systems such as the hyperbolic browser disclosed in A Focus+Context Technique Based on Hyperbolic Geometry for Visualizing Large Hierarchies, by Lamping et al., in Proceedings of ACM SIGCHI Conference on Human Factors and Computing Systems, May 1995, change the display of the document as the user navigates the information space.
A freeform digital ink whiteboard known as Tivoli is disclosed in Pen-Based Interaction Techniques For Organizing Material on an Electronic Whiteboard, by Moran, et al., in UIST ""97, ACM press. Tivoli allows users to identify a connection between two areas in a display, where that connection is maintained as those areas are moved and the display changes. Circle marks which surround other ink identify areas, and freeform digital ink marks which connect two area boundaries together form a connection between those two areas. This connection persists as the areas move and Tivoli attempts to maintain the shape of the connecting mark.
To assist in navigation of documents conventional systems use a set type of bookmark. Examples of such navigation systems are disclosed in Virtual Annotation System, by Harmon, et al., in Proceedings of the IEEE 1996 Virtual Reality Annual International Symposium, pp. 239-245 (1996) and in Worldlets:3D Thumbnails for Wavfinding in Virtual Environments, by Elvins, et al., in video proceedings of UIST ""97, pp. 21-30 (1997). These systems make it ackward for a user to freely interact with the navigation system because the user is required to specify an annotation command before commenting.
Current systems attempt to manage freeform digital ink annotation on changing views or displays by at least one of three methods (the terms xe2x80x9cviewxe2x80x9d and xe2x80x9cdisplayxe2x80x9d are used interchangeably throughout this application). The first method, known as the static approach, treats ink annotations as associated with a single view. When the presentation or the content of the document changes, the annotations either disappear or remain in their original positions. A system known as xe2x80x9cMATExe2x80x9d which is disclosed in A Marking Based Interface for Collaborative Writing, by Hardock et al., in Proceedings of UIST ""93 (1993), addresses changing content by maintaining a static annotated version, a changed version without annotation and logical links between these two versions.
A second method, known as the snapshot approach, treats the dynamic view as a series of static snapshots which can be individually annotated. Examples of this approach include the Wang Freestyle disclosed in Rapid, Integrated Desin of a Multimedia Communication System, by Francik, in Human-Computer Interface Design, Morgan Kaufman Publishers, Inc., (1996).
The third method, known as the temporal association approach, separates the ink annotations from the view and links the two temporally, so that marks made in a specific time are associated with the view at that time. Examples of this approach are used in Marquee which is disclosed in Marquee: A Tool for Real-Time Video Logging, by Weber et al., in Proceedings of CHI ""94, ACM Press, (April 1994) and Dynomite which is disclosed in Dynomite: A Dynamically Organized Ink and Audio Notebook, by Schilit et al., In Proceedings of CHI ""97, ACM Press, (1997).
In conventional interfaces that accept freeform digital ink annotation, the indication of the logical relationships between the annotations and the associated objects are not maintained if the view changes. For example, if a user annotates the text of a document and, subsequently, the annotated text reflows across lines, the annotation does not follow the reflowed portion of the text. Therefore, while there may be an underlying logical relationship to the annotated text, the layout of the new view does not indicate this logical relationship between the text and the annotation.
The systems described as related art above also do not maintain any indication of logical relationships between the annotations and the associated objects if the view changes. Tivoli does not maintain the freeform digital ink annotations as the areas move around and the display changes. Rather, Tivoli maintains only one specific type of annotation: a single stroke from the boundary of one area to another. This restriction precludes the use of freeform digital ink annotations in changing displays to label moving objects or to aid navigation.
While MATE maintains the logical relationships between freeform digital ink annotations and the corresponding underlying text, it does not maintain the indications of these logical relationships as the view changes.
Freestyle does not allow the freeform digital ink annotations to carry over to new views of the same document
Dynomite does not permit annotations directly on the view and the annotations are not rendered on the new views in accordance with changes to the views.
The method and system of the invention maintain the layout relationships between freeform digital ink annotations and objects in changing views. As a user makes a freeform digital ink annotation on a view and as the view changes, the method and system of the invention adapt the marks in accordance with the changes. Thus, the logical relationship between the freeform digital ink annotations and the objects made in one view can be understood in future views based upon the layout relationships.
The method and system also maintain the indication of the logical relationships between freeform digital ink annotations and objects in dynamic media such as video and interactive virtual worlds. For example, if a user, who is exploring an information space with a hyperbolic browser, makes a freeform digital ink annotation on a node of the tree, when the user changes the display to bring another portion of the tree into focus, the freeform digital ink annotation rotates and scales along with the tree to continue to indicate the logical relationship of the freeform digital ink annotation to the node.
The methods and systems of this invention maintain the indication of the logical relationships between freeform digital ink annotations and objects in a view as the view of the annotated objects changes. This invention brings the experience of marking on paper to dynamic media, changing word-processor documents, information visualizations, virtual worlds, digital video and word processors.
The system and method of the present invention maintain the indication of the logical relationship, even if the objects that are logically related to the freeform digital ink annotations are deleted, inserted, copied or moved or otherwise altered. The method and system also maintain the indication of the logical relationship if the layout presentation of the objects in the display change because the objects reflow, scale, resize, rotate, stretch, distort or morph or if any other aspect of the layout presentation changes, regardless of whether these changes occur discretely or continuously.
Additionally, another exemplary embodiment of the systems and methods of the invention provides navigational markers that make freeform digital ink annotation a powerful tool for navigating dynamic documents. A user is permitted to select a freeform digital ink annotation in an arbitrary view, and the display is returned to the state it was in when the selected freeform digital ink annotation was made.